| Abstract |
The objective of Team Porous is to develop a process for the fabrication of porous superhydrophobic surfaces that can be used as samples for research in a laboratory setting. Superhydrophobicity is a property which is defined as an extreme repulsion to water and is accomplished by combining the effects of surface geometry and material properties of a surface. A byproduct of superhydrophobic surfaces is that they experience little to no skin drag due to fluid flow over the surface compared to a controlled case. However, in cases where there is flow over the surface or where the surface is submerged for extended periods of time, water can be forced into the surface geometry which contributes to the superhydrophobic properties which causes the drag reduction to no longer be effective. The project set out before us was to develop a porous tile which a superhydrophobic coating will be attached to and which allows air to be distributed to the coated surface to displace any water that may have saturated it. We were given this project by Dr. Hangjian Ling, to assist in his research towards using the properties of superhydrophobic surfaces to reduce the drag experienced by marine vessels and improve fuel efficiency. We have determined that additive manufacturing, specifically Masked Stereolithography (MSLA) using UV sensitive resin, will be the best method of manufacturing the tile within the budgetary, time, and general constraints that we were given. The Tile went through many iterations and different designs over the course of the project as we identified certain techniques and features that made it easier or more difficult to produce the results we wanted. The first design was a “hole grid” with a pattern of small pores that pierced through the entire tile to allow air to pass through, and small posts between them to provide the necessary surface roughness for superhydrophobicity. However, these holes were too small for the printer to reliably create them, and so the design was modified and improved until we reached our current design, which features long slits in the tile, instead of holes, and has ridges serving as the required surface geometry to replace the posts in earlier designs. This improved design is the result of many hours of testing and iterations, and corrects many issues with previous designs, so that it may be able to accomplish the testing that is required of it. |
